Hi Denis, the answer to this question is whether or not you have work experience. If you have two plus years of work experience than you would be a viable Contender for an MBA, depending upon what you've done of course. If you have a track record of leadership and impact that would position you well. Of course there are many many other factors.
Your thoughts about a GPA of 3.3 keeping you out of a top 20 school could not be more misguided. I have countless examples but I'm thinking off the top of my head of someone who I got into MIT Sloan who had a 3.3 and NYU Stern who had a 3.0. The first one had a GMAT of 700 and the second had a GMAT of 730, which is not really that high for an IT Indian applicant, but his strongest qualification given that he did not have any extracurricular involvement, international experience, or hobbies. Your GMAT score means a great deal more than your GPA in this process.
You would also need to have good solid recommenders. Are you thinking about applying next month? Or round two? I would imagine probably round 2 because you didn't mention the GMAT. If you have the work experience I've mentioned then I would focus on getting the GMAT nailed and then take it from there.. if you don't have any work experience, right now, an MBA is really just not a fit for you. You would consider a master's in economics maybe from the London School of Business or potentially a masters in management.
If you want an MBA then you need to have that work experience to really appreciate what you're learning in business school and put it in context.
Good luck!
Farrell
https://MBAPrepCoach.COM